System and method for continuous growth of large-size high-quality nitride single crystals using flux method

Abstract

The present invention discloses a system and method for continuously growing large-sized, high-quality nitride single crystals using a flux method. The system includes: a reaction growth unit, a raw material supply unit, a waste recovery unit, a growth stagnation monitoring unit and a control unit. The reaction growth unit includes a reaction chamber for reaction growth of nitride single crystals. The raw material supply unit and the waste recovery unit are respectively connected to the reaction chamber. The waste recovery unit is at least used to guide the waste in the reaction chamber. The growth stagnation monitoring unit is at least used to monitor the growth state of the nitride single crystal, and the control unit is also connected to the raw material supply unit, the waste recovery unit, and the growth stagnation monitoring unit. The system provided by the present invention has a raw material supply unit for automatically and uniformly replenishing raw materials. By continuously replenishing the growth raw materials during the growth process, the automatic, continuous and uniform growth of gallium nitride single crystals is achieved.

Description

Technical Field

[0001] The invention relates to a system for growing nitride single crystals by a flux method, and in particular to a system and method for continuously growing large-size and high-quality nitride single crystals by a flux method, belonging to the technical field of crystal preparation. Background Art

[0002] The growth technology of gallium nitride (GaN) single crystals obtained by the flux method (Na Flux method) is currently one of the internationally recognized methods for obtaining low-cost, high-quality, large-size gallium nitride bulk single crystals. The general growth process of gallium nitride bulk single crystals is: select appropriate raw materials (mainly metal gallium, metal sodium, carbon additives, etc.) composition ratio, place the crucible containing the growth raw materials and gallium nitride seed crystals in a growth furnace, and obtain gallium nitride bulk single crystals of different thicknesses by liquid phase epitaxy on the gallium nitride seed crystals at a certain growth temperature and a certain growth pressure nitrogen atmosphere by controlling different growth times. However, during the growth process, the gallium nitride single crystals continue to grow, and the growth raw materials are also continuously consumed (especially the consumption of metal gallium), until the liquid level of the growth raw materials is lower than the gallium nitride epitaxial growth surface, and the growth stops.

[0003] In order to obtain large-sized GaN bulk single crystals, extending the growth time is very effective. As the growth time increases, the raw materials in the crucible are consumed and the GaN single crystal grows thicker. On the one hand, the liquid level of the growth raw materials will be insufficient to cover the GaN epitaxial growth surface, resulting in growth stagnation; on the other hand, the ratio range of the raw materials in the growth system will deviate from the optimized growth raw material ratio range, resulting in subsequent growth imbalance, poor crystal quality, and growth rate deviation from the optimal growth state.

[0004] Therefore, how to achieve stable and continuous growth of GaN single crystals in a growth system is a technical problem that needs to be solved urgently in order to obtain large-sized, high-quality GaN single crystals. Summary of the invention

[0005] The main purpose of the present invention is to provide a system and method for continuously growing large-size high-quality nitride single crystals by a flux method, so as to overcome the deficiencies in the prior art.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0007] An embodiment of the present invention provides a system for continuously growing large-size high-quality nitride single crystals by a flux method, which comprises: a reaction growth unit, a raw material supply unit, a waste recovery unit, a growth stagnation monitoring unit and a control unit, wherein the control unit is respectively connected to the reaction growth unit, the raw material supply unit, the waste recovery unit and the growth stagnation monitoring unit;

[0008] The reaction growth unit comprises a reaction chamber for reaction growth of nitride single crystals, the raw material supply unit and the waste recovery unit are respectively connected to the reaction chamber, the raw material supply unit is at least used to provide the reaction chamber with raw materials required for growing nitride single crystals, and the waste recovery unit is at least used to guide waste out of the reaction chamber.

[0009] The growth stagnation monitoring unit is at least used to monitor the growth state of the nitride single crystal, and

[0010] The control unit is at least used to adjust the working states of the raw material supply unit and the waste recovery unit according to the monitoring signal of the growth stagnation monitoring unit.

[0011] Another aspect of the present invention is to provide a method for continuously growing large-sized, high-quality nitride single crystals using a flux method, which comprises:

[0012] Provide a system for continuously growing large-size, high-quality nitride single crystals using the flux method;

[0013] The raw materials required for growing the nitride single crystal are loaded into the reaction chamber of the reaction growth unit, and the growth conditions are adjusted to grow the nitride single crystal;

[0014] The growth state of the nitride single crystal is monitored by a growth stagnation monitoring unit, and based on this, it is determined whether it is necessary to use a waste recovery unit to discharge the waste in the reaction chamber and / or to use a raw material supply unit to input the raw materials required for growing the nitride single crystal into the reaction chamber, so that the nitride single crystal can grow continuously to the required specifications.

[0015] Furthermore, the method for continuously growing large-size, high-quality nitride single crystals by the flux method specifically includes: using the X-ray growth monitoring device to collect the intensity signal of the nitride characteristic peak in the reaction chamber, obtaining the height difference between the raw material liquid level in the reaction chamber and the epitaxial growth surface of the nitride single crystal according to the intensity signal of the nitride characteristic peak, and comparing the height difference with a set threshold value, so as to determine whether the growth of the nitride single crystal is stagnant,

[0016] If so, the waste in the reaction chamber is discharged by the waste recovery unit and / or the raw material supply unit is used to input the raw material required for growing the nitride single crystal into the reaction chamber, so that the nitride single crystal continues to grow; if not, the waste recovery unit and / or the raw material supply unit are not started; preferably, if the growth of the nitride single crystal stagnates, the waste in the reaction chamber is first discharged by the waste recovery unit, and then the raw material supply unit is used to input the raw material required for growing the nitride single crystal into the reaction chamber, so that the nitride single crystal continues to grow.

[0017] Compared with the prior art, the advantages of the present invention include:

[0018] 1) The system provided by the embodiment of the present invention has a raw material supply unit for automatically and uniformly replenishing raw materials, and realizes automatic, continuous and uniform growth of gallium nitride single crystals by continuously replenishing growth raw materials during the growth process;

[0019] 2) A system and method for continuously growing large-size, high-quality nitride single crystals by a flux method provided in an embodiment of the present invention also realizes continuous replenishment of raw materials for growing nitride single crystals in a reaction chamber through a raw material supply unit and a waste recovery nitrogen source, and ensures consistency in the ratios of various raw materials for growing nitride single crystals, thereby avoiding the problem that the ratio range of residual waste in the reaction chamber to the raw materials to be supplied deviates from the optimal growth ratio range;

[0020] 3) The embodiment of the present invention provides a system for continuously growing large-sized, high-quality nitride single crystals using a flux method, which has a simple structure and is easy and convenient to operate and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of a system for continuously growing large-size, high-quality nitride single crystals using a flux method provided in a typical implementation case of the present invention;

[0022] Figure 2 It is a schematic diagram of the principle structure of a system and method for continuously growing large-size, high-quality nitride single crystals using a flux method provided in a typical implementation case of the present invention;

[0023] Figure 3 It is a schematic flow chart of a method for continuously growing large-size, high-quality nitride single crystals using a flux method provided in a typical implementation case of the present invention;

[0024] Figure 4 The diagram is a schematic diagram of the structure of a nitride device prepared using the system. DETAILED DESCRIPTION

[0025] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0026] In order to overcome the problems in the prior art, the embodiments of the present invention provide a system and method for continuously growing large-size, high-quality nitride single crystals using a flux method. The system and method achieve continuous replenishment of raw materials for growing nitride single crystals in a reaction chamber through a raw material supply unit and a waste recovery nitrogen source, and ensure the consistency of the ratios between the various raw materials used to grow nitride single crystals, thereby avoiding the problem that the residual waste in the reaction chamber causes the ratio range of the raw material to be supplied to deviate from the optimized growth ratio range.

[0027] In addition, the waste recovery unit can guide the remaining raw materials out of the reaction chamber after the single crystal growth is completed to prevent the residual metallic sodium and metallic gallium from adhering to the gallium nitride single crystal, making it easy to clean after the gallium nitride single crystal is taken out. It can also prevent the metal from solidifying on the surface of the gallium nitride single crystal, which would cause the gallium nitride single crystal to be subjected to greater stress and crack during the cooling process due to different thermal expansion coefficients, thereby facilitating the acquisition of high-quality, complete gallium nitride bulk single crystals.

[0028] Based on the relationship between raw material ratio and growth rate, controlling and maintaining the stability of the raw material ratio can effectively improve the growth rate of GaN bulk single crystals grown by the flux method. The carbon additive content has a significant effect on the effect of inhibiting polycrystalline formation in the flux-grown GaN. Therefore, the recycling of waste is extremely important. Timely removal of waste can achieve consistency in the raw material ratio, obtain a faster growth rate, improve GaN growth efficiency, reduce the time cost of single crystal growth, avoid the formation of polycrystals and adversely affect crystal quality.

[0029] The embodiment of the present invention provides a system for continuously growing large-sized, high-quality nitride single crystals by a flux method. A growth stagnation monitoring unit is arranged in the growth system to timely replenish raw materials through a raw material replenishing unit when the raw material liquid level is lower than the epitaxial growth surface of the gallium nitride single crystal. The growth stagnation monitoring unit includes an X-ray growth monitoring device. For example, when the growth is stagnant, the waste in the reaction chamber is discharged through the waste recovery unit to ensure that the ratio of the raw materials to be replenished is not affected by the waste composition, and then the raw material replenishing unit is used to automatically replenish raw materials of a certain ratio, thereby realizing high-efficiency automatic replenishment of the raw materials, and then realizing stable and continuous growth of the gallium nitride single crystal, and finally obtaining a large-sized, uniform-quality gallium nitride bulk single crystal.

[0030] Specifically, during the process of loading raw materials into the reaction chamber for the growth of gallium nitride single crystal, the intensity signal of the characteristic peak of gallium nitride is obtained in real time through the X-ray growth monitoring device. By judging the strength of the characteristic peak, the height of the molten raw material liquid level from the epitaxial growth surface of the gallium nitride single crystal can be obtained. If the height is lower than the set threshold, it is judged that the growth has stopped, and a growth stop signal is sent to the control unit. The control unit controls the waste recovery unit to start waste recovery and suck out the residual waste in the reaction chamber. After the waste recovery is completed, the control unit controls the raw material replenishment unit to automatically supply raw materials to the reaction chamber.

[0031] An embodiment of the present invention provides a system for continuously growing large-size, high-quality nitride single crystals using a flux method. A melt uniformity detection device (e.g., a flow meter) is also provided at the first flow conduit in the raw material supply unit to determine the uniformity of the raw material supply, prevent uneven distribution or proportioning of the raw material components, and ensure uniform supply of the growth raw materials. The stirring device in the raw material supply chamber has a high-temperature alloy stirring blade to achieve the effect of corrosion resistance of the stirring blade at high temperatures.

[0032] Specifically, an embodiment of the present invention provides a system for continuously growing large-size high-quality nitride single crystals by a flux method, which includes: a reaction growth unit, a raw material supply unit, a waste recovery unit, a growth stagnation monitoring unit and a control unit, wherein the control unit is respectively connected to the reaction growth unit, the raw material supply unit, the waste recovery unit, and the growth stagnation monitoring unit;

[0033] The reaction growth unit comprises a reaction chamber for reaction growth of nitride single crystals, the raw material supply unit and the waste recovery unit are respectively connected to the reaction chamber, the raw material supply unit is at least used to provide the reaction chamber with raw materials required for growing nitride single crystals, and the waste recovery unit is at least used to guide waste out of the reaction chamber.

[0034] The growth stagnation monitoring unit is at least used to monitor the growth state of the nitride single crystal, and

[0035] The control unit is at least used to adjust the working states of the raw material supply unit and the waste recovery unit according to the monitoring signal of the growth stagnation monitoring unit.

[0036] Further, the raw material supply unit includes at least one raw material supply chamber and at least one gas supply device, the raw material supply chamber is used to accommodate at least one raw material required for growing nitride single crystals, and the raw material supply chamber is connected to the reaction chamber through a feeding pipeline;

[0037] The gas supply device is connected to the raw material supply chamber via a first gas conduit, and is at least used to provide inert gas to the raw material supply chamber, thereby forming a first gas pressure difference between the raw material supply chamber and the reaction chamber, and the first gas pressure difference can drive the raw material in the raw material supply chamber to flow into the reaction chamber.

[0038] Furthermore, the raw material supply chamber is a sealed chamber.

[0039] Furthermore, the feed pipeline enters the reaction chamber from the bottom of the reaction chamber, and the outlet of the feed pipeline is far away from the epitaxial surface of the nitride single crystal.

[0040] Furthermore, a flow meter is also provided in the feeding pipeline, and the flow meter is at least used to monitor the uniformity of the raw materials flowing through the feeding pipeline.

[0041] Furthermore, a stirring device is also provided in the raw material supply chamber; preferably, the stirring device is also connected to a speed monitoring and regulating device, and the speed monitoring and regulating device is also connected to the control unit.

[0042] Furthermore, the raw material supply unit includes a plurality of raw material supply chambers, and the plurality of raw material supply chambers are respectively used to accommodate at least one raw material required for growing different structural layers of the nitride single crystal.

[0043] Further, the waste recovery unit includes at least one waste recovery chamber and at least one exhaust device, the waste recovery chamber is at least used to accommodate waste in the growth reaction chamber, and the waste recovery chamber is connected with the reaction chamber through a discharge pipeline;

[0044] The exhaust device is connected to the waste recovery chamber via a second air duct, and is at least used to exhaust the gas in the waste recovery chamber, thereby forming a second air pressure difference between the waste recovery chamber and the reaction chamber. The second air pressure difference can drive the waste in the reaction chamber to flow into the waste recovery chamber.

[0045] Furthermore, the waste recovery chamber is a sealed chamber.

[0046] Furthermore, the feed inlet of the discharge pipeline is arranged at the bottom of the reaction chamber.

[0047] Furthermore, the growth stagnation monitoring unit includes an X-ray growth monitoring device.

[0048] Another aspect of the present invention is to provide a method for continuously growing large-sized, high-quality nitride single crystals using a flux method, which comprises:

[0049] Provide a system for continuously growing large-size, high-quality nitride single crystals using the flux method;

[0050] The raw materials required for growing the nitride single crystal are loaded into the reaction chamber of the reaction growth unit, and the growth conditions are adjusted to grow the nitride single crystal;

[0051] The growth state of the nitride single crystal is monitored by a growth stagnation monitoring unit, and based on this, it is determined whether it is necessary to use a waste recovery unit to discharge the waste in the reaction chamber and / or to use a raw material supply unit to input the raw materials required for growing the nitride single crystal into the reaction chamber, so that the nitride single crystal can grow continuously to the required specifications.

[0052] Furthermore, the method for continuously growing large-size, high-quality nitride single crystals by the flux method specifically includes: using the X-ray growth monitoring device to collect the intensity signal of the nitride characteristic peak in the reaction chamber, obtaining the height difference between the raw material liquid level in the reaction chamber and the epitaxial growth surface of the nitride single crystal according to the intensity signal of the nitride characteristic peak, and comparing the height difference with a set threshold value, so as to determine whether the growth of the nitride single crystal is stagnant,

[0053] If so, the waste in the reaction chamber is discharged by the waste recovery unit and / or the raw material supply unit is used to input the raw material required for growing the nitride single crystal into the reaction chamber, so that the nitride single crystal continues to grow; if not, the waste recovery unit and / or the raw material supply unit are not started; preferably, if the growth of the nitride single crystal stagnates, the waste in the reaction chamber is first discharged by the waste recovery unit, and then the raw material supply unit is used to input the raw material required for growing the nitride single crystal into the reaction chamber, so that the nitride single crystal continues to grow.

[0054] Furthermore, the method for continuously growing large-size, high-quality nitride single crystals by the flux method specifically includes: inputting inert gas into the raw material supply chamber by the gas supply device in the raw material supply unit, thereby forming a first gas pressure difference between the raw material supply chamber and the reaction chamber, and using the first gas pressure difference to drive the raw material in the raw material supply chamber to flow into the reaction chamber.

[0055] Furthermore, the method for continuously growing large-size, high-quality nitride single crystals using the flux method specifically includes: using a vacuum device in a waste recovery unit to extract the gas in the waste recovery chamber, thereby forming a second gas pressure difference between the waste recovery chamber and the reaction chamber, and using the second gas pressure difference to drive the waste in the reaction chamber to flow into the waste recovery chamber.

[0056] Furthermore, the method for continuously growing large-size, high-quality nitride single crystals using the flux method specifically includes:

[0057] The raw materials required for growing the nitride single crystal are loaded into the reaction chamber of the reaction growth unit, and the seed crystal is also placed in the reaction chamber, and the growth conditions are adjusted to grow the nitride single crystal. The raw materials for growing the nitride single crystal are grown in the reaction chamber to form the nitride single crystal;

[0058] An X-ray growth monitoring device is used to collect the intensity signal of the characteristic peak of nitride in the reaction chamber, and thereby determine whether the growth of the nitride single crystal is stagnant. If the reaction is stagnant, the residual waste in the reaction chamber is first discharged through a waste recovery unit, and then at least one raw material required for growing the nitride single crystal is input into the reaction chamber through a raw material supply unit, so that the raw material liquid level in the reaction chamber is higher than the epitaxial growth surface of the nitride single crystal, and at the same time, the ratio of various raw materials in the reaction chamber reaches a preset value, so that the reaction of growing and forming the nitride single crystal occurs continuously, and then a large-sized and high-quality nitride single crystal continues to grow; further, the nitride single crystal includes a gallium nitride single crystal.

[0059] Furthermore, the raw material is a molten raw material.

[0060] Further, the raw material includes metal gallium, metal sodium and a carbon additive, or the raw material includes metal aluminum, metal barium and a carbon additive.

[0061] The technical solution, its implementation process and principle, etc. will be further explained in conjunction with the accompanying drawings and specific embodiments as follows. It should be noted that the process conditions for growing gallium nitride single crystals by the flux method adopted in the embodiments of the present invention can be achieved by using process conditions known to those skilled in the art, and will not be elaborated on herein. Among them, the X-ray growth monitoring device, the exhaust device, the gas supply device, the flow meter, the stirring device and the heating device, the speed monitoring and regulating device, etc. adopted in the present invention can all adopt existing known equipment, which can all be obtained commercially. The control unit adopted in the present invention can be a PLC controller, etc., and the numerical control program adopted therein can all be obtained commercially.

[0062] Example 1

[0063] See also Figure 1 A system for continuously growing large-size high-quality nitride single crystals by a flux method includes: a reaction growth unit, a raw material supply unit, a waste recovery unit, a growth stagnation monitoring unit and a control unit.

[0064] Specifically, the reaction growth unit includes a reaction chamber 100 for reaction growth of nitride single crystal.

[0065] Specifically, the raw material supply unit includes a raw material supply chamber 210 and a gas supply device 250. The raw material supply chamber 210 is at least used to accommodate the raw material required for growing the nitride single crystal. The raw material supply chamber 210 is connected to the reaction chamber 100 through a feeding pipeline 230. The gas supply device 250 is connected to the raw material supply chamber 210 through an air inlet pipeline 260 and is at least used to provide inert gas to the raw material supply chamber 210, and a first gas pressure difference is formed between the raw material supply chamber 210 and the reaction chamber 100. The first gas pressure difference can drive the raw material in the raw material supply chamber 210 to flow into the reaction chamber along the feeding pipeline 230.

[0066] Specifically, the waste recovery unit includes a waste recovery chamber 310 and an exhaust device 330. The waste recovery chamber 310 is at least used to accommodate waste in the growth reaction chamber 100. The waste recovery chamber 310 is connected to the reaction chamber 100 through a discharge pipeline 320. The exhaust device 330 is connected to the waste recovery chamber 310 through a second exhaust pipe 340, and is at least used to extract the gas in the waste recovery chamber 310, and form a second air pressure difference between the waste recovery chamber 310 and the reaction chamber 100. The second air pressure difference can drive the waste in the reaction chamber 100 to flow into the waste recovery chamber 310 along the discharge pipeline 320.

[0067] Specifically, the growth stagnation monitoring unit includes an X-ray growth monitoring device, which is at least used to monitor the growth state of the nitride single crystal, and the control unit is also connected to the gas supply device 250, the gas exhaust device 330, and the X-ray growth monitoring device. The control unit is at least used to adjust the working states of the raw material supply unit and the waste recovery unit according to the monitoring signal of the growth stagnation monitoring unit. The control unit mainly adjusts the working states of the raw material supply unit and the waste recovery unit by adjusting the working states of the gas supply device 250 and the gas exhaust device 330.

[0068] For details, please refer to Figure 2 The raw material supply chamber 210 is also provided with a stirring device 220 and a heating device. The heating device can heat the raw material to heat the raw material in the raw material supply chamber 210 to the growth temperature required for growing a nitride single crystal. The stirring device 220 can make the raw material in the raw material supply chamber 210 mixed and heated more evenly to avoid local overcooling; of course, the stirring device 220 and the heating device can be arranged in one piece, and the stirring device can also be connected to the speed monitoring and regulating device, and the speed monitoring, regulating device and the heating device are all connected to the control unit.

[0069] Specifically, a flow meter 240 is also provided in the feeding pipeline 230. The flow meter 240 is connected to the control unit and is at least used to monitor the uniformity of the raw material flowing through the feeding pipeline 230 to ensure that nitride single crystals of uniform quality are obtained. The flow meter 240 is connected to the flow rate display screen so that real-time flow rate parameters can be displayed. When the raw material is uneven, the stirring device arranged in the sealed chamber 210 is controlled to rotate to improve the uniformity of the raw material and ensure the uniform supply of the growth raw material.

[0070] Specifically, the control unit includes a control screen, through which the working parameters of each device can be set.

[0071] Specifically, the feed pipe 230 enters the reaction chamber 100 from the bottom of the reaction chamber 100, and the discharge port of the feed pipe is away from the epitaxial surface of the nitride single crystal. The raw materials enter from the bottom of the reaction chamber 100, away from the epitaxial growth surface of the nitride single crystal. This can ensure that the growth raw materials have enough time to be fully mixed and diffused again before reaching the epitaxial growth surface of the nitride single crystal, thereby preventing the problem of excessive local saturation near the epitaxial growth surface of the nitride single crystal, thereby inhibiting the occurrence of spontaneous nucleation polycrystalline phenomenon.

[0072] Specifically, the raw material supply chamber 210 and the waste recovery chamber 310 can be arranged in the same container and separated by a partition 400, or, the raw material supply chamber 210 and the waste recovery chamber 310 can be respectively arranged in different sealed containers, wherein the raw material supply chamber 210 can be one or more, and the multiple raw materials required for growing nitride single crystals can be placed in the same raw material supply chamber 210 according to a preset ratio, or the multiple raw materials required for growing nitride single crystals can be placed in multiple raw material supply chambers 210 according to a preset ratio, and each raw material supply chamber 210 contains one raw material.

[0073] See also Figure 2-Figure 4 Taking the flux method for growing gallium nitride crystals as an example, the following Figure 1 The growth of gallium nitride crystals is performed using a system for continuously growing large-size high-quality nitride single crystals using a flux method as shown in the figure, which may specifically include the following process:

[0074] A seed crystal for growing a gallium nitride single crystal is placed in a reaction chamber 100, and raw materials for growing a gallium nitride single crystal (such as metal gallium, metal sodium, and carbon additives) are used in the reaction chamber 100 to grow a gallium nitride single crystal under conditions of 3-10 MPa and about 800° C. As the gallium nitride single crystal continues to grow, the growth raw materials are consumed.

[0075] Specifically, the X-ray growth monitoring device collects the intensity signal of the characteristic peak of gallium nitride in the reaction chamber, and the X-ray growth monitoring device obtains the height difference between the liquid level of the molten raw material in the reaction chamber and the epitaxial growth surface of the gallium nitride single crystal according to the intensity signal of the characteristic peak of gallium nitride, and compares the height difference with the set threshold value, so as to determine whether the growth of the gallium nitride single crystal is stagnant.

[0076] When the growth stops, the gas extraction device 330 is used to extract the gas in the waste recovery chamber 310, and a second pressure difference is formed between the waste recovery chamber 310 and the reaction chamber 100, so that the waste in the reaction chamber 100 flows into the waste recovery chamber 310 driven by the second pressure difference. Then, the gas supply device 250 inputs an inert gas (such as argon, etc.) into the raw material supply chamber 210, and a first pressure difference is formed between the raw material supply chamber 210 and the reaction chamber 100, and the raw material in the raw material supply chamber 210 is driven to flow into the reaction chamber 100 by the first pressure difference, so that the liquid level of the molten raw material in the reaction chamber 100 is higher than the epitaxial growth surface of the nitride single crystal, and at the same time, the ratio of multiple raw materials in the reaction chamber reaches a preset value, so that the reaction of growing and forming nitride single crystals occurs continuously, thereby obtaining large-sized and high-quality nitride single crystals.

[0077] Specifically, the waste in the reaction chamber is discharged through the waste recovery unit to ensure that the raw material ratio to be replenished is not affected by the waste composition, and a certain ratio of raw materials is replenished into the reaction chamber through the raw material supply unit to achieve consistency of the raw material ratio, so that the gallium nitride single crystal can grow uniformly and continuously, thereby ensuring the uniformity of the gallium nitride crystal quality.

[0078] Specifically, the raw material replenishment unit can be used to replenish one or more of the multiple raw materials used to grow gallium nitride single crystals. One or more raw materials can be placed in a raw material replenishment chamber according to a preset ratio. Alternatively, multiple raw material replenishment chambers 210 can be set up to place the multiple raw materials required for growing nitride single crystals in multiple raw material replenishment chambers 210 according to preset ratios.

[0079] For example, using Figure 1 The process of growing gallium nitride crystals in a system for continuous growth of large-size high-quality nitride single crystals by a flux method as shown in FIG. 1 may include:

[0080] placing a seed crystal for growing a gallium nitride single crystal in a reaction chamber;

[0081] First, a gas supply device is controlled to supply gas to a raw material supply chamber containing a doped silicon raw material, so as to input the doped silicon raw material into a reaction chamber to grow N-type gallium nitride;

[0082] Then, an X-ray growth monitoring device is used to collect the intensity signal of the characteristic peak of nitride in the reaction chamber, and thereby determine whether the growth of the nitride single crystal is stagnant. If so, the residual doped silicon waste is recovered from the reaction chamber to the waste recovery chamber by controlling the exhaust device to exhaust gas;

[0083] Next, the non-doped raw material contained in another raw material supply chamber is input into the reaction chamber by controlling the gas supply device to supply gas to the raw material supply chamber, so as to grow the non-doped layer;

[0084] Similarly, after the non-doped layer grows to a certain thickness, the residual non-doped waste is recovered from the reaction chamber to the waste recovery chamber by controlling the operation of the exhaust device;

[0085] Afterwards, the doped metal Mg raw material contained in a raw material supply chamber is input into the reaction chamber by controlling the gas supply device to supply gas to the raw material supply chamber to grow a P-type gallium nitride layer, thereby forming a PIN structure of gallium nitride epitaxy, such as Figure 4 shown.

[0086] It is worth noting that after the growth of each structural layer is completed, the raw material recovery unit is used to recover the growth raw materials of this ratio, so as to avoid the presence of residual raw material impurities used to grow the previous structural layer in the reaction chamber when the next structural layer is grown, thereby avoiding affecting the performance of the PIN structure.

[0087] Specifically, the ratio of metallic gallium, metallic sodium, and carbon additives in the reaction raw materials for growing nitride single crystals directly affects the growth quality of the gallium nitride single crystals. Therefore, maintaining the optimal raw material ratio is very important for the growth of high-quality gallium nitride. During the reaction, metallic sodium, as a flux, can promote the breaking of the N2 triple bond and increase the solubility of nitrogen atoms in the molten mixed raw materials, wherein metallic gallium and nitrogen atoms combine to form a bulk gallium nitride single crystal. During the reaction, metallic sodium is not consumed. As metallic gallium is continuously consumed, the ratio between the raw materials deviates from the initial ratio of the reaction, which leads to uneven growth quality of the gallium nitride single crystal. Therefore, the recovery of residual waste is extremely important.

[0088] It should be noted that the present invention is not limited to the preparation of this type of structural nitride single crystal. Those skilled in the art can also prepare different nitride device structures by increasing the number of raw material replenishment slots, changing the raw material ratio and the type of doping elements, so that the preparation of the device structure can be completed by loading the furnace once, thereby reducing the cost of preparing the device structure. A system for continuously growing large-sized, high-quality nitride single crystals by a flux method provided in an embodiment of the present invention has a simple structure and is easy and convenient to operate and use. In addition, the system provided in an embodiment of the invention has a raw material replenishment unit for automatically and uniformly replenishing raw materials. By continuously replenishing the growth raw materials during the growth process, the automatic, continuous and uniform growth of gallium nitride single crystals is achieved.

[0089] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A system for continuously growing large-size, high-quality nitride single crystals using a flux method, characterized in that It includes a reaction growth unit, a raw material supply unit, a waste recovery unit, a growth stagnation monitoring unit and a control unit, wherein the control unit is connected to the reaction growth unit, the raw material supply unit, the waste recovery unit and the growth stagnation monitoring unit respectively; The reaction growth unit includes a reaction chamber for reaction growth of nitride single crystals, the raw material supply unit and the waste recovery unit are respectively connected to the reaction chamber, the raw material supply unit is at least used to provide the reaction chamber with the raw material required for growing the nitride single crystal, and the waste recovery unit is at least used to discharge the waste in the reaction chamber; the raw material supply unit includes at least one raw material supply chamber and at least one gas supply device, the raw material supply chamber is at least used to accommodate at least one raw material required for growing the nitride single crystal, and the raw material supply chamber is connected to the reaction chamber through a feeding pipeline; the gas supply device is connected to the raw material supply chamber through a first gas guide pipeline, and is at least used to provide inert gas to the raw material supply chamber, thereby forming a first gas pressure difference between the raw material supply chamber and the reaction chamber, and the first gas pressure difference The material supply chamber can drive the material in the material supply chamber to flow into the reaction chamber; the waste recovery unit includes at least one waste recovery chamber and at least one exhaust device, the waste recovery chamber is at least used to accommodate the waste in the growth reaction chamber, and the waste recovery chamber is connected with the reaction chamber through a discharge pipeline; the exhaust device is connected with the waste recovery chamber through a second gas guide pipeline, and is at least used to extract the gas in the waste recovery chamber, and a second gas pressure difference is formed between the waste recovery chamber and the reaction chamber, and the second gas pressure difference can drive the waste in the reaction chamber to flow into the waste recovery chamber, and the raw material supply unit and the waste recovery unit are used to realize the continuous replenishment of the raw material for growing nitride single crystals in the reaction chamber and ensure the consistency of the ratio between the various raw materials for growing nitride single crystals; The growth stagnation monitoring unit is at least used to monitor the growth state of the nitride single crystal, and the growth stagnation monitoring unit includes an X-ray growth monitoring device, and the X-ray growth monitoring device is used to collect the intensity signal of the nitride characteristic peak in the reaction chamber, obtain the height difference between the raw material liquid level in the reaction chamber and the epitaxial growth surface of the nitride single crystal according to the intensity signal of the nitride characteristic peak, and compare the height difference with a set threshold value, so as to determine whether the growth of the nitride single crystal is stagnant. If so, the waste in the reaction chamber is discharged by the waste recovery unit and / or the raw material supply unit is used to input the raw material required for growing the nitride single crystal into the reaction chamber, so that the nitride single crystal continues to grow. If not, the waste recovery unit and / or the raw material supply unit are not started; and The control unit is at least used to adjust the working states of the raw material supply unit and the waste recovery unit according to the monitoring signal of the growth stagnation monitoring unit.

2. The system for continuously growing large-size high-quality nitride single crystals by flux method according to claim 1, characterized in that: The feeding pipeline enters the reaction chamber from the bottom of the reaction chamber, and the outlet of the feeding pipeline is far away from the epitaxial surface of the nitride single crystal.

3. The system for continuously growing large-size high-quality nitride single crystals by flux method according to claim 2, characterized in that: A flow meter is also provided in the feeding pipeline, and the flow meter is at least used to monitor the uniformity of the raw materials flowing through the feeding pipeline.

4. The system for continuously growing large-size, high-quality nitride single crystals by flux method according to claim 2, characterized in that: The raw material supply chamber is also provided with a stirring device, and the stirring device is also connected to a speed monitoring and regulating device, and the speed monitoring and regulating device is also connected to the control unit.

5. The system for continuously growing large-size high-quality nitride single crystals by flux method according to claim 1, characterized in that: The raw material supply unit includes a plurality of raw material supply chambers, and the plurality of raw material supply chambers are respectively used to accommodate at least one raw material required for growing different structural layers of the nitride single crystal.

6. The system for continuously growing large-size, high-quality nitride single crystals by flux method according to claim 1, characterized in that: The feed inlet of the discharge pipeline is arranged at the bottom of the reaction chamber.

7. A method for continuously growing large-size high-quality nitride single crystals using a flux method, characterized in that include: Provide a system for continuously growing large-size, high-quality nitride single crystals using a flux method as described in any one of claims 1 to 6; The raw materials required for growing the nitride single crystal are loaded into the reaction chamber of the reaction growth unit, and the growth conditions are adjusted to grow the nitride single crystal; An X-ray growth monitoring device is used to collect the intensity signal of the characteristic peak of nitride in the reaction chamber, and the height difference between the raw material liquid level in the reaction chamber and the epitaxial growth surface of the nitride single crystal is obtained according to the intensity signal of the characteristic peak of nitride, and the height difference is compared with a set threshold value, so as to judge whether the growth of the nitride single crystal is stagnant. If so, the waste in the reaction chamber is discharged by the waste recovery unit and / or the raw material required for growing the nitride single crystal is input into the reaction chamber by the raw material supply unit, so that the nitride single crystal continues to grow. If not, the waste recovery unit is not started. The material recovery unit and / or the raw material supply unit; if the growth of the nitride single crystal stops, the waste in the reaction chamber is first discharged by the waste recovery unit, and then the raw material supply unit is used to input the raw material required for growing the nitride single crystal into the reaction chamber, so that the nitride single crystal continues to grow. The raw material supply unit and the waste recovery unit are used to continuously replenish the raw materials for growing the nitride single crystal in the reaction chamber and ensure the consistency of the ratios between the various raw materials used for growing the nitride single crystal, so that the nitride single crystal can grow continuously to the required specifications.

8. The method for continuously growing large-size high-quality nitride single crystals by flux method according to claim 7, characterized in that: The method specifically includes: inputting inert gas into the raw material supply chamber by a gas supply device in the raw material supply unit, thereby forming a first gas pressure difference between the raw material supply chamber and the reaction chamber, and driving the raw material in the raw material supply chamber to flow into the reaction chamber by the first gas pressure difference.

9. The method for continuously growing large-size high-quality nitride single crystals by flux method according to claim 7, characterized in that: The method specifically includes: using a vacuum device in a waste recovery unit to extract the gas in the waste recovery chamber, thereby forming a second pressure difference between the waste recovery chamber and the reaction chamber, and using the second pressure difference to drive the waste in the reaction chamber to flow into the waste recovery chamber.

10. The method for continuously growing large-size high-quality nitride single crystals by flux method according to claim 7, characterized in that Specifically include: The raw materials required for growing the nitride single crystal are loaded into the reaction chamber of the reaction growth unit, and the seed crystal is also placed in the reaction chamber, and the growth conditions are adjusted to grow the nitride single crystal; An X-ray growth monitoring device is used to collect the intensity signal of the characteristic peak of nitride in the reaction chamber, and thereby determine whether the growth of the nitride single crystal is stagnant. If so, the waste in the reaction chamber is first discharged by a waste recovery unit, and then at least one raw material required for growing the nitride single crystal is input into the reaction chamber by a raw material supply unit, so that the raw material liquid level in the reaction chamber is higher than the epitaxial growth surface of the nitride single crystal, and at the same time, the ratio of various raw materials in the reaction chamber reaches a preset value, so that the nitride single crystal continues to grow.

11. The method for continuously growing large-size high-quality nitride single crystals by flux method according to claim 7, characterized in that: The nitride single crystal includes a gallium nitride single crystal.

12. The method for continuously growing large-size high-quality nitride single crystals by flux method according to claim 7, characterized in that: The raw material is a molten raw material.

13. The method for continuously growing large-size, high-quality nitride single crystals by flux method according to claim 7, characterized in that: The raw material includes metal gallium, metal sodium and a carbon additive, or the raw material includes metal aluminum, metal barium and a carbon additive.

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